This invention relates to apparatus for filling tanks with soft drink and like beverages. More particularly, the invention comprises an arrangement for effecting an accurate fill of such tanks.
Beverage containers or tanks of the type with which the present invention is concerned are typically large metal caps which are ultimately used to dispense the beverage at refreshment stands and similar locations. The tanks may be, for example, of five-gallon (19 liter) capacity which are filled with premix or postmix product. When premix is provided, syrup, water and carbon dioxide are first mixed in desired proportions, and the resultant product is delivered to the tanks. When postmix is provided, syrup only is delivered to the tank and the end product is mixed in its final form at the dispensing site.
U.S. Pat. No. 316,098 to Hayden et al. discloses one approach of tank handling apparatus, wherein the fluid, whether premix product or postmix syrup, is supplied through a manifold and hose or supply line, and carbon dioxide is supplied through a gas manifold and hose or supply line. The supply lines for the gas and fluid are each attached by suitable fittings to the tanks, and the tank is first charged with a quantity of carbon dioxide. Thereafter, the liquid is introduced into the tank; the rate of tank filling being controlled by the charge of carbon dioxide already in the tank. A series of tanks may be serviced at one time.
During the tank filling process, the carbon dioxide first is introduced into the tank through a tube and fitting at or near the tank top. Thereafter, the product is introduced through a tube which extends to the tank bottom, so that the rising level of liquid in the tank forces some of the carbon dioxide out of the tank and back through the carbon dioxide supply line. Thus, in order to fill the tank, the pressure of the liquid in the liquid supply line is greater than that of the carbon dioxide in the tank and in the carbon dioxide supply line. When the tank is filled to a predetermined level of liquid, the liquid will enter a fill height tube in the top of the rank. This fill height tube communicates with the carbon dioxide supply line and, in effect, forms an extension or continuation thereof. The rising level of liquid in the fill height tube ultimately closes a check valve which is incorporated in a known manner in the coupler that connects the carbon dioxide supply tube to the fill height tube.
Upon closing of the check valve, carbon dioxide can no longer escape from the carbon dioxide head at the top of the tank. Unless the liquid supply is cut off, the liquid will continue to be supplied to the tank until the tank is filled or until the pressure head developed by the carbon dioxide equals the liquid supply line pressure, and thus becomes sufficient to prevent further filling of the tank with liquid. In general, however, a result of the foregoing procedure is that the tank sometimes overfilled with liquid. In any case, the accuracy of the fill levels obtained by the foregoing arrangement is frequently less than what is desired.